I. FIELD OF THE INVENTION
This invention relates generally to a surgical instrument for selectively irrigating and aspirating fluids during the course of a surgical procedure, and more particularly such an instrument which is readily suitable for use in endoscopic procedures. It is particularly characterized in that the fluid conveying portions of the instrument are disposable while the flow control elements thereof are reusable.
II. DISCUSSION OF THE PRIOR ART
When conducting minimally invasive surgical procedures, such as abdominal surgery using laparoscopic procedures, rather than creating a large incision, three or four small puncture wounds are formed through the abdominal wall which permit a series of cannulae to be inserted therethrough. One cannula will accommodate an endoscope (laparoscope) allowing the internal surgical site to be illuminated and the scene displayed on a video screen. Another cannula may typically provide for the introduction of special surgical instruments for dissecting and excising tissue while yet another cannula accommodates an instrument for grasping and manipulating the origin or other tissue to be excised.
While the use of laser-based instruments or electrosurgical instruments can be used to effect coagulation of blood seeping from severed blood vessels, it frequently becomes necessary during the course of an endoscopic procedure to irrigate within the body cavity to remove blood and other body fluids which may obstruct the view being presented to the surgeon. On an as needed basis, a suction/irrigator may have a portion thereof passed through a cannula and then, by manipulating appropriate flow control devices, a liquid, such as saline, can be used to flush the surgical site. Subsequently, a vacuum may be applied to aspirate the saline and other body fluids to restore the view of the surgical field and the tissue being excised as the surgical procedure takes place.
A typical prior art suction/irrigator for endoscopic use includes an elongated rigid tube which is adapted to be passed through the lumen of a cannula and which is adapted to be coupled to a supply of flushing liquid and/or to a vacuum source, via one or more flow control valves. Typical of such a prior art suction/irrigator instrument is that sold by the Cabot Company of Langhorne, PA. The flow control valves in that reusable device are similar to trumpet valves, whereby depression of one or the other of a pair of spring loaded push buttons allows either the flushing liquid to pass down the rigid tubular portion of the instrument into the surgical site or, alternatively, allows blood and other body fluids to be drawn from the surgical site through the rigid tube and the flow control valves to a collection vessel coupled to a source of vacuum. Because the fluids flow through the trumpet valves, when it comes time to clean and sterilize the instrument following a first surgery to make it ready for a subsequent procedure with a different patient, the valve and valve housing must be disassembled for cleaning and sterilization and then later reassembled and relubricated. Because it is difficult to get access to all of the surfaces that may come in contact with body fluids, it makes it difficult to clean and sterilize for reuse. Also, because of the materials selected and complexity of the valving system, the instrument tends to be too costly to be considered "single-use" or "disposable".
The Storz suction/irrigation probe manufactured by Wisap of West Germany is partially a reusable device utilizing a pinch valve to control the fluid flow through a tube. In this device, only a part of a fluid path is disposed of after use. The instrument's elongated rigid tube designed to pass through a cannula must be manually cleaned with pipe cleaners etc. and the entire reusable unit must be rinsed and/or autoclaved. Still another prior art suction/irrigator is a totally disposable unit also made and sold by Cabot. While this suction/irrigator probe has been manufactured at a sufficiently low cost so as to be considered entirely disposable, the cost reduction has been accomplished with sacrifice in quality, ease of handling and other ergonomic considerations. Moreover, its cost necessarily exceeds the cost of the present invention for reasons that will become apparent as the description thereof proceeds.
It is accordingly a principle object of the invention to provide a suction/irrigator surgical instrument in which the entire fluid path of the instrument is designed to be disposable, but where the higher cost flow control members contained within a handle-like housing are reusable and designed to be readily cleaned and sterilized for subsequent use with a simple, low-cost replacement cartridge containing the instrument's fluid path.